title: Genome-wide expression analysis of rice aquaporin genes and development of a functional gene network mediated by aquaporin expression in roots.
abstract: The world population continually faces challenges of water scarcity for agriculture. A common strategy called water-balance control has evolved to adapt plant growth to these challenges. Aquaporins are a family of integral membrane proteins that play a central role in water-balance control. In this study, we identified 34 members of the rice aquaporin gene family, adding a novel member to the previous list. A combination of phylogenetic tree and anatomical meta-expression profiling data consisting of 983 Affymetrix arrays and 209 Agilent 44 K arrays was used to identify tissue-preferred aquaporin genes and evaluate functional redundancy among aquaporin family members. Eight aquaporins showed root-preferred expression in the vegetative growth stage, while 4 showed leaf/shoot-preferred expression. Integrating stress-induced expression patterns into phylogenetic tree and semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) analyses revealed that 3 rice aquaporin genes were markedly downregulated and 4 were upregulated by water deficiency in the root, suggesting that these candidate genes are key regulators of water uptake from the soil. Finally, we constructed a functional network of genes mediated by water stress and refined the network by confirming the differential expression using RT-PCR and real-time PCR. Our data will be useful to elucidate the molecular mechanism of water-balance control in rice root.
authors.affiliation: Department of Plant Molecular Systems Biotechnology and Crop Biotech Institute, Kyung Hee University, Yongin, 446-701, Korea.
authors.forename: Minh Xuan
authors.initials: MX
authors.lastname: Nguyen
authors.forename: Sunok
authors.initials: S
authors.lastname: Moon
authors.forename: Ki-Hong
authors.initials: KH
authors.lastname: Jung
mesh_terms: D020346:Aquaporins / Q000235:genetics* / Q000378:metabolism; D055864:Droughts; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D053263:Gene Regulatory Networks; D012275:Oryza / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D018517:Plant Roots / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013312:Stress, Physiological; D014867:Water / Q000502:physiology
chemical_list: D020346:Aquaporins; D014867:Water